6666729 has 4 divisors (see below), whose sum is σ = 8888976. Its totient is φ = 4444484.

The previous prime is 6666719. The next prime is 6666749. The reversal of 6666729 is 9276666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6666729 - 2¹² = 6662633 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (6666719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1111119 + ... + 1111124.

It is an arithmetic number, because the mean of its divisors is an integer number (2222244).

Almost surely, 2^6666729 is an apocalyptic number.

It is an amenable number.

6666729 is a deficient number, since it is larger than the sum of its proper divisors (2222247).

6666729 is a wasteful number, since it uses less digits than its factorization.

6666729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2222246.

The product of its digits is 163296, while the sum is 42.

The square root of 6666729 is about 2582.0009682415. Note that the first 3 decimals coincide. The cubic root of 6666729 is about 188.2077923535.

It can be divided in two parts, 66 and 66729, that added together give a triangular number (66795 = T₃₆₅).

The spelling of 6666729 in words is "six million, six hundred sixty-six thousand, seven hundred twenty-nine".